Simplify the following expression: ${-2(4z+9)+9(3+8z)}$
Solution: Distribute the ${-2}$ into the first set of parentheses: $ {-2(}\gray{4z+9}{)} + 9(3+8z) $ $ {-8z-18} + 9(3+8z) $ Distribute the ${9}$ into the parentheses: $ -8z-18 + {9(}\gray{3+8z}{)} $ $ -8z-18 + {27+72z} $ Rewrite the expression to group the ${z}$ terms and numeric terms: $ {-8z + 72z} {-18 + 27}$ Combine the ${z}$ terms: $ {64z} {-18 + 27}$ Combine the numeric terms: $ {64z} + {9}$ The simplified expression is $64z+9$